Dr. Kruse on the Results of a Study Comparing Outcomes in Pleomorphic Vs Non-Pleomorphic Invasive Lobular Carcinoma

Megan Kruse, MD, medical oncologist, Cleveland Clinic, discusses the results of a study comparing clinical features and outcomes of pleomorphic vs non-pleomorphic invasive lobular carcinoma.

During the 2021 San Antonio Breast Cancer Symposium, findings from a retrospective study were presented, which demonstrated key differences between pleomorphic and non-pleomorphic invasive lobular carcinoma in terms of clinical features and outcomes.

The results showed that, compared with non-pleomorphic disease, patients with pleomorphic disease were less likely to be estrogen receptor positive, more likely to be HER2 positive, more likely to have grade 3 tumors, less likely to be diagnosed at a lower T stage, and less likely to be diagnosed with axillary lymph node involvement.

Patients with pleomorphic disease were also more likely to receive chemotherapy and HER2-directed therapy. These differences may have been driven by the differences in HER2 positivity between groups.

Additionally, patients with pleomorphic disease were found to have more advanced disease at presentation in the breast, but not in the lymph nodes, compared with patients with non-pleomorphic disease. This was an expected finding as pleomorphic disease is thought to be more aggressive vs classical invasive lobular carcinoma. However, although pleomorphic disease is thought to be more aggressive, a positive trend toward improved 10-year recurrence-free survival and overall survival was observed in the pleomorphic group vs the non-pleomorphic group.